1. Technical Field
The present utility model relates to a device for board member curved surface forming which is mainly used for the forming of the adjustable segmented mold such as outer board plate members of hull with 3D curved surface and processing by plastic punching, and belongs to mechanical engineering field.
2. Description of Related Art
For the manufacturing of curved surface board parts, the traditional forming method mainly includes punching formation. However, punching formation is primarily used in large batch production. The processing of a part by this forming method generally requires several sets of integral type molds. The machined pieces formed by punching feature high precision and good quality, but there are still some problems such as high mold manufacturing cost and long production period.
With the rapid growth of the economy in China, the shipbuilding industry is developing quickly. The members similar to the hull plates in shipbuilding feature very low batch size, complicated shape, large scale and small curvature. It is almost impossible to machine an integral type mold for processing due to expensive costs. Therefore, for hull plate members with simple curvature in the prior art, three-core roller or oil hydraulic press is generally used for processing; while for hull plate members with complicated curvature, based on a primary formation, manual line heating is adopted for longitudinal bending. As is known to all, the plate forming process of line heating has the disadvantages of poor production conditions, high labor strength, high requirement for technical skills of the workers and low production efficiency.
Therefore, people began discussing the multi-ram and multi-point board formation.
The existing representative technical literature includes:
Literature 1: “Multi-point board formation device” for board punching (Patent Number: 02273508.9), etc.;
Literature 2: Patent DE4213490C1 and others used for airplane sheet skin technique;
Literature 3: the technical solution of “Japanese multi-ram plate bending machine” for shipbuilding (Ship-Building Technology, China Communications Press, December 1980, Page 141-149).
The ram in Literature 1 has a spherical surface. When punching formation, it contacts the plate at “multiple points”. The dents on the plates after punching are obvious and the compressed and deformed parts of the plate may generate harmful crumpling and deformation. To avoid crumpling and deformation, additional edge-pressing cylinder, edge-pressing ring or pad or similar measures shall be provided around the mold. Unfortunately, this is still impossible to properly solve the problems of big dents and crumpling and deformation. The ram in Literature 2 has a spherical surface capable of swinging along with the plate shape, but the contacting with the plate is also points-based and the contact area is larger. To keep the smoothness of the plate, rubber pads or elastic pads shall be put under the plate to be processed, but the problems of big dents and crumpling and deformation still fail to be properly solved. The ram in Literature 3 has a disk-shaped surface capable of swinging along with the plate shape. Although the contact area of the ram and plate is much larger than that above, many parts of the plate exposed between every two disk rams fail to be pressed, which may lead to the compressed and deformed parts of the plate generating harmful crumpling and deformation. In addition, due to the instability of the compressed parts of the plate, the pair of up & down-aligned rams are driven to swing, this still makes the plate generate harmful crumpling and deformation. It can be concluded from the literature above that the ram has either a disk-shaped surface or a spherical surface. It is a technical difficulty for multi-ram board and multi-point board formation processing to prevent the generation of crumpling and deformation and reduce dents during punching of boards.